I'm in great need of help with this. Basically my t7700 which should run at 2.4GHz on a multiplier of x12 has changed itself into a t7700 that runs at 0.6GHz on a x3 multiplier. I have Dell XPS M1330, which to my knowledge has no BIOS access to timings / voltages etc. My memory has been affected also.
On benchmarking the t7700 is running at 25% and memory at 30%. However all the diagnostics i've tried have said the memory and cpu are present and working.
I'm at a complete loss as to how to proceed? I tried to download the Intel 64 bit processor diagnostic tool but couldn't as i had a newer version of Visual C ++ already installed.
Every other thing i've tried has failed or merely indicated that the cpu and memory were present.
The issue that you are describing seem to be BIOS related.
I would suggest installing the latest BIOS version for your DELL* system, if that does not help, please proceed to contact DELL* so they can provide you further support on it.